1/2 c. chopped onions
1/4 c. butter
1/4 c. flour
1/8 tsp. pepper
2 1/4 c. milk
1 c. shredded cheese
1/2 tsp. dry mustard
1/2 tsp. salt
4 c. thinly sliced potatoes
1 lb. ham (2 c.), cut in lg. chunks

Cook butter and onion in large saucepan until onion is tender. Blend in flour, mustard, salt and pepper. Gradually stir in milk. Cook and stir over medium heat until sauce thickens. Stir in cheese; arrange potato slices in greased 12 x8 x 2-inch baking dish. Top with ham and pour sauce over all. Cover with foil and bake in 350 degree oven for 45 minutes. Uncover and bake 15 minutes longer. Makes 4 servings.